Controlled Templating of Porphyrins by a Molecular Command Layer

The copper porphyrin (5,10,15,20-tetraundecylporphyrinato)copper(II) can be templated in a well-defined arrangement Using p-(hexadecyloxycarbonyl)phenylacetylene as a command layer on graphite. The bicomponent system was characterized at the submolecular level at a solid/liquid interface by scanning tunneling microscopy (STM). It is proposed that the layer of copper porphyrins is templated on top of the command layer in a hierarchical fashion via a combination of intermolecular pi-pi stacking and van der Waals interactions. A very subtle effect, i.e., a superstructure in the alkyl chain region of the phenylacetylene monolayers, was identified as a. decisive factor for the templating process.